1. Field of the Invention
The present invention relates to a method of treating a tobacco extract solution to eliminate magnesium ions, a method of manufacturing a regenerated tobacco material, and a regenerated tobacco material.
2. Description of the Related Art
Tobacco materials such as natural tobacco leaves, tobacco shreds, midribs, stems and roots contain various components including nicotine, proteins, alkali metals and alkaline earth metals. These components are extracted from a natural tobacco material and used as a flavor additive to tobacco. Some of these components of the natural tobacco materials should desirably be reduced in amount or removed, while the others should not be removed or even increased in amount, for a reason of smoking flavor or some other reasons.
For example, U.S. Pat. No. 3,616,801 discloses a method in which the amount of metal ions (magnesium, calcium, potassium, etc.) is reduced from an aqueous tobacco extract solution by bringing a cation exchange resin into contact with the extract, in order to improve the burning property, flavor and ash characteristics of tobacco. It is described that with the addition of the tobacco extract solution having the reduced amount of metal ions to the extraction residue, a regenerated tobacco material with improved burning, flavor and ash characteristics is obtained.